DISCOVERY 



97 



aircraft is the construction of all-metal machines. 

 This method of construction has been highly developed 

 in Germany, where the celebrated Junkers' all-dura- 

 lumin monoplanes have been much discussed for the 

 past two years. The greatest achievement, however, in 

 all-metal construction is the much talked of giant 

 monoplane built in the Zeppelin works at Staaken. 



This is the latest and largest example of an all- 

 metal aeroplane, and is the biggest monoplane flying. 

 It is constructed entirely of duralumin. The fuselage 

 is devoid of longerons, or longitudinal spars, and con- 

 sists of riveted sheet duralumin, kept rigid by a series 

 of internal duralumin girder bulkheads. Indeed, the 

 internal bracing of the fuselage is somewhat reminis- 

 cent of that of the Zeppelin airships. The fuselage 

 is of very deep cross-section. The wings arc of the 



The under-carriage is of great strength and simpli- 

 city. It consists of horizontal V struts on either side 

 carrying the wheel axle, thus avoiding a long a.xle, 

 and a third telescopic strut, ver\' deep from front to 

 back, which runs from the wheel axle to the wing, 

 midway between the engine nacelles. This strut is 

 fitted with shock absorbers. Each axle carries twin 

 sidc-by-side wheels of large size, about 4 feet in 

 diameter. 



The pilot's seat is on the top of the fuselage and 

 gives a clear all-round view. The fuselage is furnished 

 for the accommodation of eighteen passengers and a 

 crew of four or five, and has a pantry, lavatory, and 

 other luxuries. Although not particularly elegant, 

 this great mass of glittering metal is a magnificent 

 sight in flight, and bears throughout evidence of that 





ZEPPEI.IN' GI.\NT MONOPLANE IN FLIGHT. 





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German high-lift type, of very great thickness, and 

 carry the four engines, two on each wing. 



The engines are carried in nacelles, which are actually 

 built into the leading edge of the wing, which is of 

 such thickness as to permit the mechanics to crawl 

 through a tunnel in the interior to reach the engines. 

 Each engine nacelle has a seat for a mechanic, and is 

 fitted with a nose honeycomb radiator. The engines 

 are the 260 h.p. Maybach. These motors were the 

 motive-power of the Zeppelin airships, and the sound 

 of them is familiar to many people in this country. 



The wings are, like the rest of the machine, covered 

 with duralumin sheet, which is an integral part of 

 the wing structure, adding vastly to its strength and 

 rigidity, and is not, as in the ordinary wood and fabric 

 wing, a mere covering. The wings are fitted with the 

 usual type balanced ailerons. 



excellence of design and construction associated with 

 the Zeppelin works. The machine flies remarkably 

 well, in spite of its heavy wing loading, and is easil}^ 

 dismantled for transport by railway or ship. 



The main dimensions of this colossus are : Span, 

 104 feet ; length, 59 feet 6 inches ; height, 16 feet 

 8 inches ; weight empty, 11,660 lb. ; weight loaded, 

 20,196 lb. Total h.p. 1,040. The speed attained 

 during the early trials was iii miles an hour. After- 

 wards this was increased to 130 miles an hour. It 

 will be seen, therefore, that it has a considerable turn 

 of speed, and is probably the fastest large machine in 

 the world. It will permit of being flown, however, at 

 a very much more economical speed. Indeed, the above 

 figures give some food for reflection. For one thing 

 the wing loading (total weight divided by lifting surface 

 in square feet) is extremely high, about 17 lb. to the 



